1. FIELD OF THE INVENTION
This invention pertains to mobile robots or automatic guided vehicles (AGVs) and more particularly, to computer control and processing of visual images from a CCD camera in a computer controlled robotic arm.
2. DESCRIPTION OF THE RELATED ART
Present day assembly processes, such as automated flexible manufacturing systems or cells for manufacturing small, delicate parts such as integrated circuits, require that accurate workpiece transfer takes place between an automatic guided vehicle (hereinafter, AGV) and an assembly or process machine, or a workpiece storage location. The problem is highlighted in those systems in which fully automatic operation without human intervention is desired to complete the workpiece transfer. Typically, present day material handling systems require a high degree of docking or parking accuracy for such workpieces to be transferred successfully without human assistance.
Particularly where small workpieces are involved, the typical AGV is not able to ascertain the precise location of a workpiece prior to transferring it automatically between the AGV and a process machine or storage location.
Also desirable for successful workpiece transfer is for the presence or absence of a workpiece to be detectable. That is, if there is no workpiece at a process machine, that fact should be ascertainable automatically.
Related to the problem of accurate workpiece transfer is the task of ensuring accurate parking of an AGV. Often, stops or cone shaped devices are used for mechanically guiding an AGV into a docking or parking position. These mechanical devices present the disadvantages of vibrating the AGV and of finding a suitable place in which to locate and mount them.